Electrical device and molded stem therefor



9 1947 D. s. GUSTIN ELECTRICAL DEVICE AND MOLDED STEM THEREFOR QE'iginalFiled'Dec. l, 1938 ATTORNEY INVENTOR .0. J- 60677.

Patented Sept. 9, 1947 ELECTRICAL DEVICE AND MOLDED STEM THEREFOR Daniel5. Gustin, Bloomfield, N. 1., assignor a) Westinghouse ElectricCorporation, East Pittsburgh, Pa., a corporation of PennsylvaniaOriginal application December 1, 1938, Serial No.

1943, Serial No. 494,142

13 Claims.

molding of the flares, cups or base portions thereof.

The principal object of the invention, generally considered, is themanufacture of electrical devices such as discharge lamps, in which thelead-in conductors are made rigid enough to serve as outer contacts orposts in order to dispense with basing, the flares or cups being formedof glass molded therearound to form stems, either by softening andpressing glass blanks, or by pouring molten glass around the leads whileheld in place.

Another object of the invention is the manufacture of electric lamps,especially of the discharge type, in which the outer electrode leads aremade so rigid that they are adapted to engage the sockets directlywithout basing, said leads being consolidated directly with glass cupsor flares, electrodes mounted on the inner ends thereof, and the moldedglass then sealed to the bulb proper.

Other objects and advantages of the invention, relating to theconstruction and arrangement of the various parts, will become apparentas the description proceeds.

Referring to the drawings:

Figure 1 is a fragmentary elevational view, partly in section, of anelectrical discharge device embodying our invention.

Figure 2 is an end elevational view of the device of Figure 1.

Figure 3 is a fragmentary sectional view on the line III-III of Figure2, in the direction of the arrows.

Figure 4 is an axial sectional view of one of the blanks used for makingthe glass baseor flare which holds the heavy leads of a discharge orother electrical device, such as shown in Fi ure 1.

Figure 5 is an elevational view of one of the heavy leads used in makinga base for a discharge or other electrical device, such as shown inFigure 1.

Figure 6 is a fragmentary vertical sectional view, with parts inelevation, showing one embodiment of a machine for manufacturing glasscupslor bases for devices such as shown in Figure Divided and thisapplication July 10,

2 Figure 7 is an axial sectional view of the right hand end portion ofthe device illustrated in Figure l, with the end cup finished by placinwax-like material therein.

Referring to the drawings in detail, like parts being designated by likereference characters,

- and first considering Figures 1 to 5, inclusive,

there is shown, as one embodiment of the invention, an electrical device20 of the discharge type, comprising an envelope or bulb 2| in the formof an elongated hollow cylinder containing some mercury 22, the ends ofsaid envelope being closed by glass discs, cups or bases 23 and 24. Thecup 23 has incorporatedv therewith lead-in conductors 25 and 26, whilethe cup 24 has incorporated therewith lead-in conductors 21 and 28, toform stems, the conductors 25 to28, inclusive, being so rigid that theyare 'adapted to serve as outer contact posts and eliminate the necessityfor the usual basing.

The inner ends of the leads 25 and 26 carry a filament 29, serving asone electrode, and the inner ends of the conductors 21 and 28 carry 'asimilar filament 3!, serving as the other electrode. The filaments maybe formed of tungsten or other suitable material, with or without oxidecoating to render them more eflicient for the emission of electrons. Theends of the filaments 29 and 3| are connected to their lead-inconductors in any suitable manner, as by means of spot welding.

The conductors 25 to 28, inclusive, are formed of suitable material,tungsten and nickel alloys being mentioned as examples, and the. glasssealed therearound is made of such a composition that it will not crackupon cooling around the lead-in conductors. For example, if soft glassis used for the base, then nickel iron, chrome iron, dumet or otheralloys of the proper coeflicient of expansion are desirably employed asthe lead-in conductors. If (Corning code) No. 1'72 (or hard aluminumborosilicate) or No. 704 or 705 (both soft borosilicate) glass isemployed, the lead-in conductors are formed of beaded molybdenum. Or ifNo. 704 or 705 glass is employed, such conductors may consist of "Kovar"(which is a patented cobalt-nickel-iron alloy), as for application insodium and mercury vapor lamps. If No. 775 or 705 (both softborosilicate) glass, or "Nonex'? or No. 7'72 (or lead borosilicate)glass is used, then beaded tungsten leads are desirably employed tomatch the expansion of said glass.

It will be noted that the cup or base 23 has an exhaust tip 32 while thecup or base 24 is without such a tip, as it is unnecessary to exhaust atmore than one end. The tip 32 is protected by making the cup reentrantor concave outwardly, and the concave portion of both cups 23 and 24may, if desired. be finished by filling with a material 50 like sealingwax as illustrated in Fig. 7.

From a consideration of Figs. 1, 2 and 3, it

will be seen that by virtue Of the bases or cups 23 and 24 beingreentrant, an exterior recess 36 is formed in each, defined by thegenerally flat end or bottom wall portion, the outer peripheral rim orbase edge extending at an angle to said bottom wall portion, and thereinforcing bosses 40, over or on less than half the bottom wall area,and through which the lead-in conductors 26 and 26, or 21 and 28, as thecase may be, respectively extend, as shown in Fig. 3. n account of thisrecess the exhaust tube of the cup 23 may, if desired, be tipped offwithin its base, without danger of fusing or damagin the base, thethickening reinforcement or bosses 40, or in-v luring the lead-inconductors, if care is exercised and a small tipping ofi flame employed.If perchance, the extreme end of the tip 32 pro- Jects slightly, asillustrated in Fig. 1, after tipping-oil and removal of the outer end ofthe exhaust tube, the projecting end portion may, be-

fore it hardens completely, readily be pushed orv flattened so as to lieentirely within the recess 36, and not project beyond the plane of theperipheral edge portion of the cup 23. The bosses 40, which have flatoutersurfaces parallel to the bottom wall portion, are formed bythickening parts of said bottom wall portion toward or to the outersurface or plane of the peripheral rim, flange, or base edge portion,

Referring now to Fig. 6, there are shown portions of one embodiment of amachine for forming such bases as Just described and the manufacture ofone, such as designated by the reference character 23, with anexhaust'tube will be disclosed.

The machine, as shown in this figure, comprises a lower mold element 33having pockets or cavities 34 in its upper face for receiving relativelyrigid or thick one-piece lead-in conductors 25 and 26, such as thosedesignated as forming parts of the cup or glass base 23. The lower moldelement 33 also has a central aperture 36 and a shoulder 61 on the uppermold element 65, Undesired depression of the supplemental mold member 56is prevented by means of a stop 62. connected to the upper mold element35, and received in a corresponding slot in the supplemental member 56.When the upper mold element descends, the supplemental member telescopeswith the lower mold member 33 and engages an annular member 66 connectedthereto. as by means of a set screw 10.

The upper mold element 55 is provided with pockets or apertures 63 and64, receiving the upper ends of the leads 26 and 26, and desirablyhaving their upper ends vented to the atmosphere, as by means of smallapertures 65 and 66. to relieve compression as the mold closes.

In order to heat the moldable material. such as the glass blank 19 andthe upper end of the exhaust tube 31 during the process of forming thedisc cup or base for the device of Figure 1, I provide suitable flres61, 66 and 66, issuing from nozzles 11, 12 and 13, carried by piping 14,supplied with suitable combustible gas from manifold 16, carried by androtatable with hollow shaft 16, driven by suitable means so that itrotates on the rod 66, and receiving a gaseous mixture throughregistering ports 60 and 80 from the hollow collar 11, held againstrotation with the shaft 16, and receiving gas from pipe 18.

The manner of using the machine of Figure 6 for making glass cups orbases, such as designated by the reference character 23 is desirably asfollows:

The first step in the operation, is desirably to place an exhaust tube31 in the lower mold element, where it rests on the upper end of the airreceiving a glass exhaust tube 31, the lower end of which rests on theupper end of a tube 38, desirably formed of metal and adapted to carrycompressed air to said exhaust tube. The lower mold element may be heldin position in a support 33. Air may be conducted to the lower end ofthe tube by any desired means, such as 'a rubher tube from a suitablesource of supply. The

erated by a rod 56. Operable in the upper mold element 65 is a plunger51. The upper mold element carries an annular supplemental mold portion33, vertically slidablethereon and held in normal or lower position, as"by means of coil spring 69, operating between its upper surface tube 36,as shown in Figure 6. The lead-in conductors 26 and 26 are then placedin their pockets 34 and 33, in the lower mold element, as shown in thesame flgure. A section 19 of large diameter glass tubing, correspondingin volume with that of the cup to be formed, is then placed on the lowermold element 33 so that it encircles the upper end of the exhaust tube31 and the leadain conductors 26 and 26, as shown in Figure The flres61, 63 and 66 are then rotated, by turning thehollow shaft 16 by anysuitable means, not shown, until the glass of the section 13 softens anddraws around the leads 23 and 26. The action of the softened glass inwetting the leads 26 and 26 and drawing in around the upper end of theexhaust tube 31,- is facilitated by the direction of flow of the flres61, 63 and i6, and the surface tension of the nearly molten glass.

When the glass becomes sufilciently soft, the upper mold element 65 isbrought down as by a downward movement of its supporting rod 66, causingthe supplemental mold member 63 to telescope with the lower mold element33, ensue the annular member 66. and the glass to be pressed into thedesired shape between the upper and lower mold elements 56 and 33. Theglass, at the same time, is pressed into consolidating engagement withthe upper end of the exhaust tube 31, the glass above the exhaust tubeopening being thinned by the downward movement of the plunger 61, whichalso insures a good seal with the exhaust tube.

The next step in the process, is to raise the upper mold element 55,slightly, while leaving the plunger 61 in engagement with the formed cupor base 23, whereby said base is detached from the upper mold elementand remains resting on the lower mold element 33. Both upper moldelement 55 and plunger 51 are then raised out or the way.- The diaphragmor thin section of glass closing the upper end of the exhaust tube 31,is now broken before the glass has had a chance to harden, by compressedair directed upwardly through the exhaust tube. a

The completed base or cup 23, with the exhaust tube 31 sealed thereto,is then ejected or stripped from the lower mold element 33, by an upwardmovement of the air tube 38, as by means of the cam acting on a rollersecured thereto, whereupon, an operator may remove the formed base orcup completely from the machine, preparatory to making another one,

It will, of course, be understood that in order to make the base or cupforming operation continuous, I desirably have a series of mold elementsand associated parts, such as shown in the figure,

and cause the same to move along to first receive the elements 31, 25,25 and 19, heat and compress them to consolidate and form the base orcup, and then raise them for removal.

The parent Patent No. 2,324,385'may be referred to for furtherillustrations of the machine of Fig. 6 and other embodiments for makingthe cups or bases disclosed.

From the foregoing disclosure, it will be seen that I have devised anovel form of glass stem, base, or cup, particularly adapted fordischarge devices. Thecups, as formed have incorporated therewith, rigidprongs having the double function of lead-in conductors and outercontact members, thereby enabling me to dispense with a subsequentbasing operation.

Although a preferred embodiment of my invention has been disclosed, itwill be understood that modifications may be made within the spirit andscope of the appended claims.

I claim:

l. Inan electrical device, a molded glass cup, said cup being concaveoutwardly forming a cavity within a peripheral rim, bosses disposed insaid cavity and merging with said rim, lead-in conductors extendingthrough said bosses, and an exhaust tube disposed between said bosses.

'2. In an electrical device, a glass envelope, a glass base closing anopening of said envelope and attached thereto, said base havin anoutwardly opening recess, spaced bosses arranged within said recess andmerging with said rim, an exhaust tube carried by the base, extendinginto said recess, and spaced from said bosses, and lead-in conductorspassing through said bosses.

3. In an electrical device, a glass cup, said cup being concaveoutwardly forming a cavity within a peripheral rim, a boss disposed insaid cavity, a lead-in conductor extending through said boss, and anexhaust tube disposed in said cavity adjacent said boss,

4. An electric device comprising an elongated glass envelope having anend closed by a pressed glass disc fused to the said end of saidenvelope, conductors extending through and fused directly to said glassdisc and projecting outwardly therefrom to function as contact pins, acentrally arranged hollow re-entran-t projection on said glass discextending into said envelope and providing a recess in the outer surfaceof said disc, an exhaust tube depending from the inner end of saidprojection and sealed off within said recess, and means secured to saiddisc and 'covering at least the portion which is recessed.

5. An electric device, comprising a glass envelope, a glass base closingthe opening of the envelope and attached thereto, said base having anexterior recess extending substantially to the marginal edge of thebase, spaced reenforcing bosses arranged within the exterior recess andformed integral with the base, an exhaust tube carried by the base andextending into .the recess and spaced fromthe reenforcing bosses, andterminal contact units embedded in the reenforcing bosses,

the arrangement being such that access may be spaced from thereenforcing bosses, the arrange- I ment being such that access may behad to the exhaust tube through the exterior recess to fuse and tip of!the same within the recess without liability of fusing the base or thereenforcing bosses, and a reenforcing filling for the exterior recessserving to reenforce the base and having the reenforcing bosses andparts of the terminal contact units embedded within such reenforcingfilling.

7. In an electrical device, a base formed as a glass cup, said cup beingconcave outwardly forming a cavity within a peripheral rim, a part ofsaid cup being thickened to' form a boss within said cavity, and alead-in conductor sealed through said boss.

8. In an electrical device, a base formed as a molded glass cup openingoutwardly, the bottom portion of said base being thickened forming aboss, and a rigid lead passing through said thickened portion in orderthat its outer portion may function as a contact post.

9. In an electrical device, an envelope open at opposite ends, and aglass base at each end of said envelope, each base having a bottom wallportion, lying in a plane-generally perpendicular to the axis of saidenvelope, and a peripheral rim portion comprising a flange offset from,and parallel to, the plane of said bottom wall and fused to the adjacentedge of said envelope, part of each bottom wall being thickened towardthe plane of said flange and forming at least one flat-topped boss smallin area compared to the bottom wall area, and a rigid lead-in conductorsealed through each boss to function as a contact terminal.

10. An electrical device comprising a molded base member having a bottomwall portion, a reinforcing boss thereon and small in area compared withsaid wall portion, a one-piece conductor secured in said boss and rigidto serve as an outer terminal or contact post, and a peripheral rimportion on said base extending at an angle to said bottom wall portion,said boss having a flat outer surface parallel to and offset from saidbottom wall portion toward the plane of the edge of said rim portion.

11. In an electrical device, a molded base having a bottom wall portion,a part of said portion being thickened over only a relatively smallportion of its area, a one-piece rigid conductor secured to andextending through said thickened part to serve as an outer terminal orcontact post, and a peripheral rim portion on said base extending at anangle to said bottom wall portion, said thickened part having a flatouter surface parallel to 7 and ofl set from said bottom wall portiontoward the plane oithe edge of said rim portion.

12. In combination, a molded cup for an electrical device comprising abottom wall portion, a part of which is thickened for reinforcingpurnmanncns man The following references are of record in the 5 file ofthis patent:

poses over only a relatively small portion or its area, a peripheral rimencircling said thickened part, and one-piece rigid conductor meanssecured in said thickened part torserve as outer contact terminal means,said thickened part having a flat outer surface parallel to said bottomwall portion and ofiset therefrom toward the plane of the edge of saidrim.

13. An electrical device comprising a molded base with an end wall,reinforcing boss means on less than one half of said end wall area, aperipheral rim encircling said boss means, and one-piece conductor meanssecured in said boss means to serve as outer contact terminal means,said boss means having a flat outer surface parallel to and offset fromsaid end wall toward the plane of the edge of said rim.

DANIEL S. GUBTIN.

UNITED STATES PATENTS Number Name Date 2,219,574 Franeckel Oct. 29, 19402,032,232 Strickland Feb. 25,1936 2,006,818 Zimber July 2,1935 2,056,621Roberts Oct, 6, 1936 2,079,801 Grant May 11, 1937 2,098,080 Wright Nov.2, 1937 2,137,174 Marshaus Nov. 12, 1938 2,147,584 Thomas Feb. 14, 19392,216,247 Ledig et al. Oct. 1, 1940 2,235,135 Ernst-Gunther AndresenMar. 18, 1941 FOREIGN PATENTS Number Country Date 4,746 Great BritainMar. 4, 1893

